1. Field of the Invention
This invention relates generally to financial transaction cards and, more specifically, to a programmable integrated circuit card for accessing a plurality of accounts.
2. Prior Art
At present, magnetic cards such as commercial credit cards are widely used for payments, cash advances, or other financial transactions through a communication system located at a retail store or a bank facility. Data for identifying the customer, such as an account number or other identifying data is magnetically stored on the card.
When a transaction is to be performed at a retail store, a customer hands his or her card to an employee of the retail store. The employee then either manually checks the account number against a list of bad account numbers which is published by the credit card company or scans the magnetic information into a communication device. In the first case, the employee has the responsibility for approving the credit card. This can lead to serious problems when a stolen credit card is presented for payment, since the lists are usually not up to date and are also hard to read. In the second case, the magnetic account and billing information is sent to the financial institution where it either accepted or declined. Since there is no method to check the authenticity of the purchaser, the financial institution must assume that the credit card user is the customer identified upon the card, unless they have been notified that the card is stolen or lost. This assumption leads to problems when a stolen credit card, which has not been reported, is utilized for the purchase of goods.
When a credit card is utilized in a bank in order to receive a cash advance, the transaction is handled by either a teller or an automated teller machine (ATM). In the case of a teller, the process described for a retail store is repeated. In the case of an ATM, the card is placed inside of the ATM and the credit card owner enters a person identification number (PIN) which is transmitted to the credit card company along with the transaction information. When the PIN is received by the credit company, the PIN is verified and, if correct, a determination is made to either allow or deny credit. When the PIN number is found to be incorrect, most credit companies send, to the credit card owner, a request to reenter the PIN number. Thus, the user of a stolen credit card will know that the PIN number that was entered was incorrect.
In an attempt to provide greater security for credit cards, integrated circuit (IC) chips have been embedded into the credit cards. An interface is arranged on the surface or edge of the IC card to allow external equipment to access the information stored in the card. Therefore, when the IC card is inserted into a terminal device installed at, for example, a bank or retail store, the IC chip in the card is electrically connected to the terminal through the interface. The IC chip is energized from the terminal through the interface, and an identification number is entered at a keyboard in the terminal. The identification number prestored in the IC chip is read out and compared with the entered identification number in the terminal so as to determine whether or not the two identification numbers match, and whether the authorized user of the card is presenting the card.
However, in a conventional IC card, the IC chip is simply embedded in the card body, so that the terminal device must be used to identify the card user. The cost of such terminal devices is relatively high and imposes a financial strain on retail stores with relatively little capital. In addition to this disadvantage, the card holder must enter the identification number in the presence of a store clerk, so that secrecy of the identification number cannot be guaranteed.
Several U.S. patents disclose the use of integrated cards that are used to access remote systems. U.S. Pat. No. 4,959,788 (Nagata et al.) discloses an IC card having a keypad, a display, and a memory unit. The keypad is used to enter transaction information which is then stored in the memory unit. When the card is inserted into an ATM, the card configures the ATM for the pre-entered transaction and thus saves the user time at the ATM.
U.S. Pat. No. 4,918,631 (Hara et al.) discloses a "smart" IC card that also has a calculator function. The card has a keypad which can be used to enter identification information. This identification information is compared to that stored in an internal memory and if there is a match, the card will be validated. Upon validation, a light emitting diode LED will be illuminated to indicate that the card is active. The merchant will then accept the card as a valid card. Because such a LED indicator is provided, an unauthorized user may enter identification information until the correct combination is determined and thus a lost or stolen credit card may be used until the loss of the card is reported to the credit card company.
U.S. Pat. No. 4,926,480 (Chaum) discloses a card that allows cryptographically secure transactions between a tamper resistant part of the card and an external system by the IC card. The card enables a user to enter information on a keypad located thereon. The card can be used to access several different types of computer systems. The tamper resistant part contains coded information which will allow a secure protocol to be established between the tamper resistant part and the external system. The user inputs access enabling information upon the keypad which is then checked against the coded information. If there is a correspondence between the two bits of information, the card is enabled. The card is then allowed to communicate with an external system via a secure protocol.
U.S. Pat. No. 4,928,001 (Masada) discloses an integrated circuit IC card that has multiple user sections. By entering the appropriate identification code, access to one or more of the user sections is allowed.
U.S. Pat. No. 4,960,982 (Takahira) discloses an IC card comprising a microprocessor which accepts access information and checks this information with a prestored key. If the information matches the key, then the card is enabled and allows access to a mass storage device.